A wellbore often includes multiple zones (corresponding to different sections of a reservoir or to multiple reservoirs) from which hydrocarbons can be produced. The multiple zones are isolated from each other, usually by the use of one or more packers.
A conventional type of packer that has been used in a multi-zone wellbore is a dual packer that has one or more production strings extending through the packer. A typical dual packer is relatively complex, and manufacture and assembly of the dual packer is often time consuming. As a result, costs associated with using conventional dual packers can be relatively high. Moreover, if conduits for hydraulic lines and electrical lines are provided through the dual packer, then the maximum differential pressure that the dual packer can withstand is lowered. If a differential pressure applied against the packer exceeds this maximum differential pressure, then the dual packer may unset unexpectedly, which is a failure condition.